What Water to use for Brewing Beer: Full Guide!

If you are reading this, first of all, I want to congratulate you, because taking an interest in the water we use and how we treat it when brewing beer is one of the biggest steps to improving as a brewer. 

When you can incorporate the basic notions about the components of water and put this knowledge into practice, I assure you that you will achieve a before and after in the quality of your product. 

In this article, I will be going over the different types of water you can and should use for brewing, such as tap water, distilled water, filtered water, rainwater, etc., their pros & cons, the importance of pH and what to use to measure it, and much more.

Without further ado, let’s get started!

What is the best type of water for brewing beer?

For brewing beer, it is ideal to start with demineralized or “soft” water and to then add important minerals, such as calcium, magnesium, etc., and the best way to obtain this water is through the use of reverse osmosis equipment.

Beer is made up of 85% to 92% water, so it is obvious that the condition and treatment of the water will affect the final product. 

Controlling some specific parameters in the water can help us, for example, to bring out the characteristics of the hops or the malt respectively. 

Now, let’s get into the actual types of water that you can use to produce beer, starting with the most accessible one:

Tap Water

If the water we’re going to be using is tap water, it is sure to contain chlorine, as it needs it for its antibacterial properties. 

But this substance is not beneficial in the production of beer because, among many things, the yeast in contact with it will create chlorophenols. 

However, solving this issue is quite simple because leaving the pot with the water uncovered from one day to the next will cause the chlorine to evaporate completely. In cases where the volume of chlorine is very high, it is likely that a carbon filter will be necessary to remove it. 

Now that we left the water uncovered a whole day, it’s time to brew, but how do you know if the water is actually in a good state for brewing? The most basic and incomplete “analysis” is simply to taste the water (needless to say, to brew beer you need drinking water). 

It should not have any strange taste or smell. Other more harmful substances, such as arsenic, should also be avoided at all costs.

I say it is incomplete because to work with our water we must know it and for this, we must perform or get an analysis of it. This will indicate its six main minerals and the predominance of each one. 

Another important thing is the pH. Its name comes from the Latin “pondus hydrogenii” and it means “amount of hydrogen”. It is a scale that will inform us how acidic or alkaline a solution is: 7 is an equilibrium, while 1-6 will be acidic and 8-12 alkaline .

Now, how do you measure the pH? Well, for this we will use a ph-meter. Below you can read about the importance of pH, the equipment you need to measure it, and more (or click on this link which will take you to that section).

Hard Water vs Soft Water

Although water treatment may seem complex at first, we will see that there are really not many components to take into account. Here I will leave you with the most relevant ones: 

  • Calcium: Calcium is the main mineral responsible for water hardness. Usually, the first one to treat is this as the minimum range we need to make beer is 50 ppm. We should not worry about excess calcium, as it is rarely high. The maximum value could be 200, but hardly that water would be drinkable. The most accepted standard values are between 50 and 75 ppm and these values take into account that calcium will be lost during cooking. For example, during the mash, calcium is essential and some ppm will be lost there. 
  • Magnesium: It is the second main mineral that affects water “hardness” and will be an essential nutrient for the yeast during fermentation. Magnesium is not usually added since the malt during the mash will make a considerable contribution of magnesium. It is advisable to try to start with about 5 ppm. At excessive volumes (+150 ppm) magnesium can cause metallic off-flavors. Using the right amount will not only help but also enhance the beer’s flavor.
  •  Sodium: Sodium works as a taste enhancer. It is very important not to have a high volume of it (up to 100 ppm) because if we have an imbalance, the beer can acquire a very unpleasant salty taste. In addition and very importantly, it can be harmful to the yeast in excessive amounts. 
  • Chloride: Like sodium and sulfate, it is an enhancer. The particularity of chloride is that it will improve the perception of the maltiness of the beer. Do not use above 100 ppm as it can affect the bitterness. 
  • Sulfate: This mineral will accentuate the perception of bitterness. It will also contribute to dryness and will leave some harshness. It is not recommended in German beers. 
  • Carbonates and bicarbonates: In case we are looking to lower the ph it is better for them to be as low as possible. The opposite is true if we need to raise it.
  • Iron: This is a component to be avoided as it promotes oxidation. The maximum we can tolerate is 0.3 ppm.
  • Alkalinity: Water also contains ions, among them are Bicarbonates, Carbonates, and Hydroxides. These three are mainly responsible for neutralizing the acids in water. The capacity that water has to neutralize acids is known as alkalinity. The limiting range of this is 250 ppm. 

The water hardness depends on the amount of calcium and magnesium in it. Basically, water will be “softer” when it contains less magnesium or calcium. 

Therefore:  Demineralised water=soft water; Mineralised water=hard water. 

However, within this hardness there are nuances: There are two concepts called “temporary hardness” and “permanent hardness”. 

The first will be related to carbonates, while the second to chlorides and sulfates. We talk about temporary hardness because it will get reduced when we bring the wort to the boil. 

Distilled Water

Distilled water does not (or should not) contain minerals. Therefore, it would be a good jumping-off point. 

The problem is that it has a higher cost than the rest of the water alternatives and is not very different from the next type. 

It can, however, be used to dilute a more mineralized water. 

Filtered Water (Reverse Osmosis)

When talking about the results of reverse osmosis filtered water, it is usually said that “it is almost the same as distilled water”. 

This is because if, say, distilled water has 0 ppm of any one unit, perhaps osmosis water has 5 ppm. This difference in practice has almost no effect.

But first of all, what is the reverse osmosis system? Is it the only demineralization system out there? 

The reverse osmosis system consists of the filtration of minerals through a membrane that separates two liquids. 

A liquid is pushed to the other side and the membrane prevents the minerals from passing through. 

Reverse osmosis is not the only desalination method, but it has proven to be the most effective and is also the most explored one. When to filter? When you have a high number of dissolved solids, and like previously mention, from 250 ppm onwards it is already a cause for concern. 

Bottled Water

In the case of bottled water, we cannot talk about its components as each manufacturer will have different values. In general, it is useful if we are completely unaware of the values of our tap water and also do not have an osmosis system. This way, at least we will have a place to start from. 


Among the sources of drinking water is rainwater. It is generally low in minerals and alkalinity. It is acidic due to the dilution of Co2 which produces carbonic acid.

It is, however, also closely linked to its geographical area; city water or water near industrial sites may contain pollutants and the specific characteristics of the water will differ from one to another. 

Importance of pH and which pH meter to buy 

There is a rule called cost per use. This dictates that if a product has a high purchase price but we can use it for a long time or many times, in principle it will be cheaper than another product with a lower purchase price but which we can use for less time.

Basically, the equation would be the cost of the product divided by the total use time or how many times we are going to use it. 

In the brewing supplies market, we have many examples of this: one is the PET buckets vs. stainless steel kegs. The former have a very low price, however, we can not use them more than a dozen times, while the latter, although they require a greater initial investment, can last for many years. 

Therefore, we conclude that a stainless steel fermenter is cheaper than a plastic barrel in the long run, and something almost identical happens with ph meters. 

Most of the “low cost” ph meters on the market are not made for beer production but for measuring irrigation water, and since they are not built for this purpose, when we submerge them in a liquid as complex as wort we will affect their performance rather quickly. 

Most of the brewers who use or have used these devices say that after the fourth or fifth time of manipulating it, it becomes more and more complicated to get accurate readings. They also say that over time they lose confidence in the values that these devices provide. 

My recommendation is to invest in a mid-to-high-range Ph meter accompanied also by a storage and cleaning kit. In this way, we can extend the life of our instrument which, if cared for properly, can survive for quite a long time.

Once we have the ph meter, we must know which are the moments where the alkalinity levels are of fundamental importance. 

Ph throughout the brewing process 

Throughout the brewing process, the pH will not only be fundamental but it will also change, so we must know how to manage it according to our needs. 

The pH is so important that some brewers recommend discarding the wort if, at the end of the mash, it is far from the recommended figures, since, from this primary error onwards, the rest of the process will be an uphill battle.

The pH must not exceed 5.6 at any time during brewing. 

During the mash, if we achieve a level between 5.2 and 5.4 it could be considered optimal. Most of the time, what we are going to have to do is lower the ph. 

How to do it? For this, there are three acids: citric, lactic, and phosphoric

The latter is the most recommended one because, if we go over the recommended amounts, it is less likely to leave unwanted flavors, as it so happens with the first two options.  

During the boil, the ideal pH is between 5.3 and 5.4.

In this hour or hour and a half of boiling, the pH will drop between 0.1 and 0.2. Then during fermentation, it will continue to drop. It is vitally important to follow this process by measuring both density and pH every 12 hours.

Water treatment 

Once we know what the function of each mineral is, we need to know which tools are available to us to be able to alter the configuration of our water. 

Why is demineralized water used, and why is the amount of minerals simply not reduced to what is necessary? 

To remove minerals, what is usually done is to dilute the water with distilled water or reverse osmosis water. In this way, if we dilute two liters of water with 50 ppm of calcium with another two liters of osmosis water, we will have a result water with 25 ppm, but the problem is that the other components will also have been reduced by half and you cannot remove minerals one by one. 

Another example of incompatibility when removing a component is the pre-boiling of water to remove alkalinity. Yes, we will be able to remove some of it, but in the process, we will be removing a lot of calcium. 

These issues make it more convenient to start with water with a mineral charge as close to 0 as possible and then add the necessary ones on your own.

  • Calcium sulfate or calcium chloride: It is the most used to add calcium and helps to lower the pH. 
  • Sodium bicarbonate: It is used to increase alkalinity. Obviously, it will provide sodium, so it should be used in water containing a low volume of it. 
  • Magnesium sulfate or magnesium chloride: These minerals are usually relegated in relation to their calcium counterparts, as it is easy to make a mistake and add more than necessary. 

When you add the minerals to the water you have to make sure that they dissolve correctly. Sometimes, simply stirring will not be enough and you will have to use a recirculation pump. 

Is water just as important when brewing with malt extract?

In the case of extracts, it is necessary to check their indications and if they already come with the necessary minerals. If so, the right thing to do is to start with demineralized water. 


Under normal conditions, we should have no problem using our tap water. Of course, the ideal scenario would be to run an analysis of our water and, if any value is out of place, we will have to add, dilute or filter as necessary. 

Remember the concept of cost per use when purchasing a ph meter to take into account the ph throughout the cooking process. Eliminate chlorine from the water and keep the most relevant minerals such as calcium, magnesium, sodium, etc. under control. 

Surely, if this is the first time you have come into contact with all these concepts, you may be a little overwhelmed, but give yourself time to digest all this knowledge slowly.

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